Oct 19/20 Meteors and Visual Orionid Observations

Carl Hergenrother

I woke up early this morning and observed the Orionids the old-fashioned way, camping out in the backyard and counting meteors by eye. Between ~3:50 and 5:35 am local time, I counted 25 meteors including 18 ORI, 2 EGE and 5 SPO. My backyard is fairly dark for being located in a large city though no where near as dark as a rural locale. Stars down to a magnitude of 4.5 were seen. For a dark suburban site, my naked eye meteor counts give a good indication of what to expect. Darker sites will see more while the opposite is true for brighter sites.

Based on visual reports submitted to the International Meteor Organization, the Orionids are still increasing in intensity. The Zenithal Hourly Rate (ZHR) reached a value of ~40 last night. The ZHR is the rate of meteors that would be seen per hour if, and these are important ifs; 1) your sky was dark enough to see stars down to magnitude 6.5, 2) the radiant of the shower was directly overhead and 3) no obstructions in your field of view. Last year, the Orionids reached a ZHR of ~70. If the same holds true this year, tonight may see twice as many meteors as last night.

Clouds ruined the observing in San Diego resulting in no meteor detections for Bob’s camera. Here in Tucson, the clouds threatened but, for the most part, stayed away. It was another personal record-breaking night with 80 total detections including 52 Orionids. With the shower predicted to peak either tonight or tomorrow night, perhaps my record will fall again.

Obs  Date (UT)   TotTime TOT SPO NTA STA ORI EGE LMI
Carl 2008-10-20  11h 06m  80  23  0   1   52  3   1
Bob  2008-10-20  Clouds

TotTime – Total amount of time each camera looked for meteors
TOT – total number of meteors detected
SPO – Sporadics (meteors not affiliated with any particular meteor shower)
NTA – Northern Taurids
STA – Southern Taurids
ORI – Orionids
EGE – Epsilon Gemininds
LMI – Leo Minorids

Published by Carl Hergenrother

I am a professional astronomer specializing in the study of comets, asteroids and meteors. This blog will focus on my professional and amateur work in this field.

2 Comments

  1. Carl,

    I find it interesting that the Taurid rates have slacken the past few nights. One would expect that these rates would be fairly steady with a slow increase toward the November maximum. Instead, rates have been quite variable for both branches of this shower. The weather forecast appears to be favorable for tonight’s maximum of the Orionids.

    Clear Skies!

    Bob

  2. Bob,

    I hope you were able to get some great data the past 2 nights. It has been clear here as well.

    I noticed that about the Taurids as well. Sirko’s 2008 analysis has the STAs peaking around Oct 10 and the NTAs peaking on Nov 14. So maybe we are just between peaks. Even if true, the fall off is a bit drastic. I was able to see a few TAU last night both visually and in the video data.

    I was also hoping we were going to have a good display of TAU fireballs this year. I sure haven’t seen any nor have I heard of any reports.

    – Carl

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